Arthur/Merlin spoilers (This ship is my OTP, so there’s a lot and it’s very in depth) 

The banter and epicness is BACK. Seriously, every scene they had was just brilliant.

One of their first scenes -

[after Merlin calls Arthur a dollop head]

Arthur: Define ‘dollop head’

Merlin: Prince Arthur.

In another scene, Arthur walks into his chambers where Merlin is scrubbing the floor. Eventually the conversation leads to Arthur not knowing how to use a bucket/mop etc. Arthur decides to prove this wrong so takes off his shirt (of course) and then picks up the sponge. He puts on hand on the back of Merlin’s head and with the other he shoves the sponge in his face. He then drops the sponge and says ‘Would you like me to show you how I can use a bucket?’ and while Merlin is going ‘No No No…’ Arthur puts the bucket onto his head. 

Don’t get worried about this scene being mean, it’s nothing like the scene in season 2 where Merlin makes the bathwater too hot and Arthur throws the water over him. This scene is much more fun and jokey and Arthur does it in a very friendly and amused way.

Later during knight training, Arthur comes up to Merlin and is like ‘are you impressed?’ and Merlin says that he’s seen better. Arthur then does impressions of Merlin fighting like a wimp in front of the knights so when Arthur goes back to training Merlin uses his magic to make Arthur drop his sword so the knights beat him.

Merlin goes missing (for reasons I won’t give away since it’s a big part of the plot) and when he’s missing Arthur storms into Gaius and Merlin’s chambers saying he doesn’t have any socks. When Merlin returns and wakes up Arthur for breakfast, the room is a complete tip and Merlin accusingly says ‘What happened?!’ Arthur then goes on about not having a servant and Merlin says Arthur couldn’t cope without him. Arthur then begins throwing things at Merlin while Merlin shouts over him things like ‘You haven’t had your breakfast yet, have you?!’, ‘No wonder it’s so messy!’ and ‘This doesn’t look like the makings of a great king!”

Then we had what is now one of my ultimate Merlin/Arthur scenes from all the seasons. Merlin is helping Arthur get ready for the battle and Arthur says ‘it’s not like you to be nervous’. Merlin says that he isn’t nervous because he trusts in Arthur and he knows that one day Arthur will be one of the greatest Kings that ever lived, because it’s his destiny. Arthur then tells Merlin that he thinks he’s wise. Queue lots of ADORABLE smiling at each other.